Arizona Supreme Court rules on drug-related DUI case

The Arizona Supreme Court ruled on April 22 that simply having Carboxy-THC in the bloodstream is not sufficient to substantiate a DUI charge. The ruling rejected an argument from the Maricopa County Attorney’s Office that the presence of a marijuana metabolite in a driver’s system was enough to demonstrate impairment. The court said that their decision was based on medical evidence that refuted the prosecutor’s claims.

The ruling will be welcome news to the more than 40,000 Arizonans who use marijuana legally for medical reasons. Carboxy-THC can be detected in the blood for up to 30 days after use, which meant that legal users of the drug were effectively banned from driving. The ruling means that law enforcement must provide evidence that a driver is actually under the influence of marijuana if they wish to bring DUI charges.

The Arizona Supreme Court was the third venue to hear arguments regarding a traffic violation that escalated to a DUI charge after Carboxy-THC was discovered in a driver’s blood. The case was originally dismissed in criminal court, but the appeals court took a different view, saying that Arizona’s DUI laws should be interpreted more widely. The state’s highest court disagreed, and an expert witness testifying on behalf of the Maricopa County Attorney’s Office conceded that the presence of a metabolite of marijuana was not a reliable sign of impairment. A justice observed that if DUI laws were interpreted in the way prosecutors wanted, a driver could be charged with DUI several years after taking a substance as long as traces of it could still be detected in their blood.

As court rulings on DUI laws continue to change how violations are levied and prosecuted, individuals facing charges of impaired driving might benefit from working with a criminal defense attorney that focuses on DUI. That attorney could develop a defense strategy that takes shifts in legal precedent into account while trying to defend a client’s rights in court.